Phototriggered Aggregation‐Induced Emission and Direct Generation of 4D Soft Patterns

Abstract

Microscopic control of macroscopic phenomena is one of the core subjects in materials science. Particularly, the spatio‐temporal control of material behaviors through a non‐contact way is of fundamental importance but is difficult to accomplish. Herein, a strategy to realize remote spatio‐temporal control of luminescence behaviors is reported. A multi‐arm salicylaldehyde benzoylhydrazone‐based aggregation‐induced emission luminogen (AIEgen)/metal‐ion system, of which the fluorescence can be gated by the UV irradiation with time dependency, is developed. By changing the metal‐ion species, the fluorescence emission and the intensity can also be tuned. The mechanism of the UV‐mediated fluorescence change is investigated, and it is revealed that a phototriggered aggregation‐induced emission (PTAIE) process contributes to the behaviors. The AIEgen is further covalently integrated into a polymeric network and the formed gel/metal‐ion system can achieve laser‐mediated mask‐free writing enabled by the PTAIE process. Moreover, by further taking advantage of the time‐dependent self‐healing property of hydrazone‐based dynamic covalent bond, transformable 4D soft patterns are generated. The findings and the strategy increase the ways to manipulate molecules on the supramolecule or aggregate level. They also show opportunities for the development of controllable smart materials and expand the scope of the materials in advanced optoelectronic applications.

Information Storage Based on Stimuli‐Responsive Fluorescent 3D Code Materials

“…[107] Additionally, some stimuli-responsive fluorescent materials can also demonstrate color transformations with the extension of stimuli time. [108,109] Thus, when these time-dependent materials or several materials with different response time to the same stimuli are applied to 3D code systems, the 3D code systems can be endowed with time responsiveness. For these codes with time-dependence, their patterns can go through changes according to a specific timeline without applying additional treatment or stimuli, thereby achieving time-dependent information transformations.…”

“…An AIEgen/metal‐ion system was developed by Li, Tang, Kwok, and their co‐workers to realize a concise light adjustment function. [ 108 ] First, a salicylaldehyde benzoylhydrazone multi‐armed AIEgen (TPE‐4SAH) was synthesized through the reaction between TPE‐cored‐salicylaldehyde (TPE‐4SA) and 4‐methoxybenzhydrazide (AH) ( Figure a). Figure 14b depicts the AIE phenomenon of TPE‐4SAH that can be excited in the presence of both UV irradiation and metal ions.…”

“…d) The formation of the 3D code through the interfacial adhesion of the gel blocks coated with ions, the time-dependent pattern changes upon UV irradiation, and the disassembly and reassembly of the gel blocks to obtain desired code pattern. a-d) Reproduced with permission [108]. Copyright 2021, Wiley-VCH.…”

Resonance-Induced Stimuli-Responsive Capacity Modulation of Organic Ultralong Room Temperature Phosphorescence

“…Considering the picturesque attributes of photo/thermal responsive and reversible OURTP of organic resonance molecules, a rewritable smart paper, which is indispensable for environmental protection, was conceptually designed and prepared through employing of DECzPO powder as the recording medium . This rewritable paper was facilely fabricated through screen-printing technology (Figure a, Supporting Information section 6).…”

Intelligent Surface with Multi-dimensional Information Enabled by a Dual Responsive Pattern with Fluorescence and Wrinkle

“…Patterned surfaces endow materials with unique properties, such as optical characteristics, , wettability, , adhesion, or friction, , which have found widespread applications in various fields. As two important parameters, surface topography and color have served important roles in information storage, information encryption and readout, and information security − from common consumer goods to specialized technology products with far-reaching economic and social consequences. Various dynamic patterned surfaces with responsive topography or color were developed to increase the information security and anticounterfeiting. − Owing to the complexity and high cost of the involved chemistry and material, however, it is still challenging to fabricate a double-mode surface with a respectively tunable topographical and colorful pattern.…”